Abstract:

Intumescent flame retardant thermoplastic starch (TPS) as char forming agent, ammonium polyphosphate (APP) and expandable graphite (EG) were used to prepare thermoplastic starch/ethylene-vinyl acetate copolymer (TPS/EVA) foam composites by melt mixing, mill plasticizing and sulfuration foaming. The effect of thermoplastic starch content on the flame retardant, mechanical and processing properties of TPS/EVA foam composites was investigated. With the introduction of char forming agent TPS, flame retardancy and charring of TPS/EVA foam composites could be significantly improved. With increasing TPS content, tensile strength, elongation at break and tearing strength of TPS/EVA foam composites showed a downward trend after firstly rising and specific gravity showed a modest rise. The TPS/EVA foam composites had best comprehensive properties at the loading of 6%TPS, i.e. LOI 26.5%, UL-94 V-0 rating, tensile strength, elongation at break, tearing strength and specific gravity 2.395 MPa, 177.48%, 10.59 N·mm^-1, 0.21452, respectively.

Key words: TPS, EVA, compound flame retardants, flame retardants, mechanical properties

摘要：

以热塑性淀粉(TPS)为成炭剂与聚磷酸铵(APP)、可膨胀石墨(EG)复配组成膨胀型阻燃剂,通过熔融密炼、开炼塑化、硫化发泡制备了热塑性淀粉/乙烯-醋酸乙烯酯共聚物(TPS/EVA)泡沫复合材料,探讨了TPS用量对泡沫复合材料阻燃性能、力学性能的影响。结果表明,TPS的加入显著提高了TPS/EVA泡沫复合材料阻燃性能,可起到良好的成炭作用;TPS/EVA泡沫复合材料的拉伸强度、断裂伸长率以及撕裂强度随着TPS用量的增加呈现先增大后减小的趋势,相对密度则是小幅度上升。当TPS用量为6%时,TPS/EVA泡沫复合材料综合性能最好,其LOI可达26.5%且UL-94为V-0级,拉伸强度、断裂伸长率、撕裂强度以及相对密度可达2.395 MPa、177.48%、10.59 N·mm^-1、0.21452。

关键词: TPS, EVA, 复配阻燃剂, 阻燃, 力学性能